Objective To establish a new method for determination of Pb and Cd in sewage.Methods The contents of Pb and Cd in sewage were simultaneously determined by linear sweep anodic stripping voltammetry in0.1mol/L HCl -0.1mol/L KCl solution.Results The peak potentials of Pb and Cd appeared at-588mV and-780mV respectively.The recovery rates and precisions(RSD%)of Pb and Cd were90.0%-110.0%,91%-109.5%and0.41%-4.24%,0.56%-7.03%respectively.The lin-ear range of Pb and Cd was0.005-0.2mg /L.Conclusion This method could be applied for determination of Pb and Cd in sewage.

Objective To observe the effect of Hydroxycamptothecin (HCPT) on proliferation of human lung cancer cell line A549 in vitro. Method Using cell calture and MTT assay to observe the effect of HCPT on proliferation of human lung cancer cell line A549. Result Lower concentration of HCPT had no evident inhibitory effect on the human lung cancer cell line A549 after 24 h. The effect was evident when the concentration of HCPT was up to 50 ?g/mL, and the inhibitory rate was 44.17%. The inhibitory rate was 50.28% when the concentration of HCPT was up to 100 ?g/mL. The inhibitory effect of HCPT became more significant with the stimulation of the time, and the inhibitory rate of 100 ?g/mL concentration of HCPT was 70.98% after 48 h. Conclusions HCPT can inhibit the proliferation of human lung cancer cell A549 in vitro. The effect is dose and time dependent.

Objective To compare the levels of four factors between gastric mucosa of Han and Tibetan patients with chronic gastritis residing in districts at the same altitude in Qinghai Province.Methods Levels of malonic aldehyde ( MDA) , superoxide dismutase (SOD) , nitric oxide ( NO) and xanthine oxidase (XOD) in gastric mucosa of Han and Tibetan patients with chronic gastritis resident in same altitude districts were examined, and a comparative study was performed.Results Levels of MDA and SOD were significantly higher in gastric mucosa of Han patients (2 2699 ± 1.58906 nmol/mgprot and 134.6313 ±48.35329 U/mgport, respectively) than those of the Tibetan (1.7095 ± 1.19474 nmol/mgprot and 109.5056 ± 28.26794 U/mgport, respectively) (P <0.05) , which indicated there were differences in metabolism of oxygen free radicals and antioxi-dant free radicals between 2 ethnics.However, there were no differences in NO and XOD levels between two ethnical groups, which suggested no ethnical difference in metabolism of the two factors.Conclusion There is ethnical difference in MDA and SOD metabolism in gastric mucosa of Han and Tibetan patients with chronic gastritis from same altitude district, which is presumably due to the different tolerance to the hypoxia at high altitude.

OBJECTIVE:To optimize the formulation of Budesonide sustained-release tablet. METHODS:Using the cumula-tive releases in 2,4,8 h as investigation indexes,central composite design-response surface method was used to optimize the amount of hydroxypropylcellulose L(HPC-L),amount of soybean phosphatides,and filler(fixed total 200 mg)lactose- micro-crystalline cellulose mass ratio in the formulation of Budesonide sustained-release tablet,and the verification test was conducted. The release behaviors of prepared sustained-release tablet and original preparation in pH 7.2,7.0,6.8 phosphate buffer were com-pared. RESULTS:The optimal formulation was as follow as budesonide of 9 mg,HPC-L of 46.49 mg,soybean phosphatides of 9.23 mg,filler lactose-microcrystalline cellulose mass ratio of 1:2.9;the cumulative releases in 2,4,8 h were 21.9%,50.1%, 99.5%,the relative errors with predicted values (22.0%,50.0%,98.5%) were 0.45%,0.20%,1.02%(n=3),respectively. Compared with cumulative release of original preparation,the f2 was higher than 50. CONCLUSIONS:Budesonide sustained-re-lease tablet is successfully prepared,which shows similar release behavior to original preparations.

Objective To explore the safe bone channels for transverse placement of sacroiliac screws via the second sacral vertebra in the fixation of longitudinal fracture of the sacrum by digital analysis and clinical observation.Methods Firstly,abdomen CT scanning was performed in 50 healthy adult volunteers.They were 30 males and 20 females,aged from 18 to 56 years (mean,34.6 years).After their CT images were transformed by software Materialise Mimics Innovation Suite 15.0,three-dimensional (3D) models of the pelvis were generated,stored in stereolithography format,and transferred into software Imageware 12.0.In the standard antero-posterior position,the sacrum was segmented and the points of 2D image coordinate geometric boundary were extracted to generate an optimal channel for transverse placement of sacroiliac screws via the second sacral vertebra.Secondly,we admitted 10 patients with longitudinal fracture of the sacrum.They were 7 men and 3 women,aged from 20 to 51 years (average,38.3 years).By Tile classification,4 cases were type B2 and 6 type C1.All the fractures were Denis region Ⅱ ones.Pubic ramus fracture was complicated in 3 cases.After traction reduction of the tibial tubercle was conducted for patients with obvious displacement,the optimal channel was calculated on the basis of the CT data.On the lateral images of the sacrum acquired before operation by C-arm fluoroscopy,the optimal channel for transverse placement of sacroiliac screws via the second sacral vertebra was located.After the skin was marked,2.5 mm Kirschner wire was drilled and the 6.0 mm hollow screws were fixated along the Kirschner wire.Postoperative CT scanning images and 3D reconstructed models were analyzed to validate the accuracy of screw placement.Results The projection of safety bone channel on the sagittal fluoroscopy of S2 vertebral body displayed an irregular water drop shape;the projection area in males (213.9 ± 52.4 mm2) was significantly larger than that in the females (171.6 ±49.6 mm2) (P ＜ 0.05).The average length of the channel in men (135.2 ± 12.9 mm) was significantly longer than that in women (121.1 ± 10.1 mm);the average diameter of the screw in men (10.2 ± 0.9 mm) was also significantly larger than that in women (9.1 ±0.8 mm) (P ＜ 0.05).The postoperative X-ray and CT scanning images showed satisfactory positions and lengths of the screws.The screw lengths averaged 98.2 mm;the operation time averaged 25.6 min.No nerve or vascular injury,loosening or breakage of the sacroiliac screws occurred in the patients.Follow-ups for 12 to 24 months revealed no other complications.Conclusion The safety channel for transverse placement of sacroiliac screws via the second sacral vertebra can be determined using the lateral 3D reconstruction images of the sacrum in preoperative planning,which facilitates the percutaneous transverse fixation of longitudinal fracture of the sacrum.

Objective To discuss an initial clinical application of three-dimensional reconstruction of ilium bone flap. Methods From December 2006 to June 2008, bone defects of 6 patients with frac-tures of femoral shaft and tibia were repaired using vascularized iliac bone flap. After injection of contrast a-gent, CT scan was performed. Amira 4.0 Software was applied to reconstruct personalized three-dimensional structures of the iliac bone flap. The points, lines, and surfaces were marked in the personalized three-dimensional images reconstructed to provide guidance for the actual surgery. Results The person-alized three-dimensional reconstruction of iliac bone flap for the 6 individual patients were successfully used in the actual surgery. The three-dimensional structures of blood vessels, bone and adjacent relationship which had been clearly shown in the reconstructed flaps were confirmed by the actual surgical findings. All the 6 lilac bone flaps survived uneventfully. Conclusion The preoperative three-dimensional reconstruction of lilac bone flap by CT scan, angiography and digital technology can provide a useful aid for actual surgical design and harvest of the flap, minimizing intraoperative injury to blood vessels and enhancing flap survival.

We conducted the detection the Francisella spp.nucle acid from Hyalomma asiaticum asiaticum that main distribution is on railway line area from China-Kazakhstan border.The free-living ticks were collected and then identified by morphological and molecular methods.After species identification,they were detected by PCR targeting 16S rRNA and sdhA of Francisella spp.The amplified products were sequenced and the sequences was analyzed by using the Blast.A phylogenetic tree was constructed using MEGA 6 software.A total of 243 fleas were identified as H.asiaticum asiaticum.Only 35 samples were detected for Francisella spp.positive and the positive rate was 14.4％.Sequence analysis showed that two different sequences (seql and seq2) and all belong to Francisella-like endosymbionts (FLEs).Phylogenetic analyses showed that two FLEs were belong to the same cladd.This is first detection of FLEs nucleic acid from H.asiaticum Railway line area of China-Kazakhstan border.

Objective To analyze characteristics of Nef-specific T lymphocyte responses in Chinese HIV-1 recombinant subtype B/C infectors. Methods 19 HIV-1 recombinant subtype B/C infectors infected within 1 year, 40 chronic infectors infected for more than 3 years were enrolled in this cohort study. Elispot assay was used to observe HIV-1 specific T lymphocyte responses in HIV-1 recombinant subtype B/C infectors. Results Nef-specific T lymphocyte responses of interferon-gamma secretion were identified in 15 Chinese HIV-1 recombinant subtype B/C infectors infected within 1 year. The specific T lymphocytes were mainly targeted at four peptides which span from Nef 83 to 135: EVA7081.1, EVAT081.5, EVA7081.6 and EVAT081.48. Responses were identified in 29(75. 2%) infectors with more than 3 years of infection and the specific T lymphocytes were mainly targeted at three peptides which span from Nef 63 to 101 : EVA7081.43, EVA7081.44, EVAT081.45, EVA7081.47, EVA7081.48 and EVA7081.49. The average magnitude of response in infectors with less than 1 year of infection was 284. 13 SFC/106 PBMC. The average magnitude of response in infectors with more than 3 years of infection was 152. 44 SFC/106 PBMC. There was a significant difference between the two groups (U = 91. 000, P = 0. 002). Conclusions HIV-1recombinant subtype B/C infectors at different stages of diseases (less than 1 year and more thank 3 years) can recognize central region of Nef. The magnitude of Nef-specific IFN-γ secretion T lymphocyte responses in this cohort gradually decrease with disease progression.

Objective To analyze character of Nef-specific T lymphocyte responses in Chinese HIV-1 recombinant subtype C/B' and subtype B' infectors and to identify the common immunodominant re-gions recognized by these infectors. Methods Fifty-nine HIV-1 recombinant subtype C/B' infectors and 27 subtype B' infectors were tested by IFN-γ enzyme linked immunospot (ELISPOT) assay using HIV-1 C/B' Nef overlapping peptides. Results Nef-specific T-cell responses of IFN-γ secretion were identified in 44 (74.58%) out of 59 HIV-1 recombinant subtype C/B' infectors. Ten peptides, EVA7081.1,5, 6, 7,43, 44, 45, 47, 48, 49 were mainly recognized. Amino acid position was from Nef63 to 115 and 117 to 139. Twenty of 27 (74.07%) HIV-1 subtype B' infectors recognized peptides. EVA7081.1,2, 43 and 49 were mainly recognized. Amino acid position was from Nef 63 to 77 and 87 to 119. There was no correlation be-tween the Nef-specific IFN-production of HIV-1-specific T cells responses and viral load or CD4 T cell count in both subtype infectors. Conclusion The immunodominant regions, from Nef63 to 77 and 87 to 115 were recognized by both Chinese HIV-1 recombinant subtype C/B' infectors and subtype B' infectors. These re-gions could be used in design of vaccine.

BACKGROUND:Many scholars at home and abroad have already attempted to apply the technique of the internal fixation pedicle screw placement to cure children’s spinal injuries in recent years, because the children’s thoracic pedicle is more smal , anatomical structure variation is big and adjacent relationship is complicated, so the application of adult’s pedicle screw technology simply to children who was in a continuous growth and development can increase operation risk greatly. Above this, improving the accuracy of nailing and reducing error rate become keys for further development of cervical pedicle fixation. OBJECTIVE:To provide an individualized and accurate positioning method for screw placement in thoracic pedicle of children by computer aided design and rapid prototyping technology. METHODS:After computed tomography scan of four cases of child specimens, the original data were made for three-dimensional reconstruction by the software, then the specimens were randomly divided into two groups:one group used the traditional pedicle internal fixation method, and the other group, first created the individual navigation template using the principle of reverse engineering and rapid prototyping technology. The lumbar pedicle screws were put into the samples by the individual navigation template. The position of the pedicle screws was evaluated according to the computer tomography scan. RESULTS AND CONCLUSION:The accurate rate of screw placement of the traditional pedicle internal fixation method was 58%;and the accurate rate of screw placement of the individual digital navigation template method was 81%. The success rate was better than the traditional surgery group. Furthermore, chi square test showed that there was a significant difference between two groups (P<0.05). These findings suggested that there has a high accuracy of the screw placement in thoracic pedicle of children assisted by the individual navigation template, ful y reflects the principle of individualization of screw placement, and provides a new feasible method for accurate screw placement in thoracic pedicle of children.